Novel Light-Weight Moldable Permanent-Magnet Material

A novel, light‐weight, moldable permanent‐magnet material is described. Elongated‐single‐domain (ESD) particles of iron‐cobalt are coated with a thermosetting plastic which serves as matrix. The particles are aligned while the plastic is in a liquid phase. The matrix is then solidified, and the agglomerate ground to a −30 mesh freeflowing powder. Each of the particles of this powder consists of submicroscopic elongated aligned particles. The freeflowing powder can then be directionally pressed in conventional presses to produce magnets of complex shape held to precision dimensions. Energies of ${\text{2.0×10}}^6$ gauss‐oersteds have been achieved in magnets whose density is 4 g/cm³ and whose temperature coefficient is 0.008%/°C. The material's properties make it well suited to applications where a light‐weight, high energy, precision‐dimensioned easily fabricated magnet, capable of withstanding adverse environmental conditions is required. An excellent application of this material is the moving‐magnet‐instrument rotor.